TOKYO, July 28, 2025 (BSS/AFP) - Four-time Grand Slam champion Naomi Osaka said Monday that she has split with coach Patrick Mouratoglou after less than a year.

"Merci Patrick... it was such a great experience learning from you," the former world number one said on X.

The Japanese star teamed up with the Frenchman, the long-time coach of 23-time Grand Slam champion Serena Williams, in September last year.

Osaka did not play in 2023 after the birth of her daughter and has struggled for consistency after returning to the professional circuit a year ago and is currently ranked 49.

She exited this year's French Open in the first round and Wimbledon in the third round.